Method and machine for filled bag production

ABSTRACT

A machine for producing bags from heat sealable web material, wherein the continuously advancing material web is tubularly wrapped by edge overlapping on a fixed and preferably horizontal mandrel, and sealed at the overlapping zone by grazing along a heated bar and then cut to lengths by a rotary knife, which lengths fall down onto an intermittent conveyor carrying such lengths to a bottom sealing device which is effective during the conveyor dwell.

United States Patent [191 Goglio METHOD AND MACHINE FOR FILLED BAG PRODUCTION [76] inventor: Lugiti Goglio, Via Solari 10. Milan,

Italy [22] Filed: Nov. 15, 1973 [21] Appl. No.: 416,273

[58] Field of Search 53/29, 24, 124 A, 124 CC, 53/124 TS, 179, 183, 187, 373, 384, 253,266

[451 Sept. 9, 1975 Primary Examiner-Robert L. Spruill Attorney, Agent, or Firm-Steinberg and Blake 5 7 ABSTRACT A machine for producing bags from heat sealable web material, wherein the continuously advancing material web is tubularly wrapped by edge overlapping on a fixed and preferably horizontal mandrel, and sealed at the overlapping zone by grazing along a heated bar and then cut to lengths by a rotary knife, which lengths fall down onto an intermittent conveyor carrying such lengths to a bottom sealing device which is [56] References Cited effective during the conveyor dwell.

UNITED STATES PATENTS 2,481,61 l 9/!949 Moore 53/124 A 12 Claims, 19 Drawing Figures K A, o O I A 44.8 o 2 45 m 501 I o 61B 295 X l PATENYEQ SEP 9 i975 SIZE? PM'MED 91% SEE PATENTEI] SEP 9 I975 SHEET PATENTEDSEP 91975 3. 903.672

SHEET 8 PATENIEI] SEP SIQYS SHEET PATENTEB SEP 9 I975 SHEET SHEET 1 1 METHOD AND MACHINE FOR FILLED BAG PRODUCTION This invention relates to a method and machine for producing and, advantageously, also for filling and closing heat-scalable flexible bags, as provided from strip or web material.

According to a known type of machine, a tube is formed on a mandrel from a web of heat-scalable material. The tube is divided into a bag by sealing and cutting. The tube thus formed and hence the material are intermittently fed, which causes the following drawbacks:

a. the tube being formed on the mandrel will be hardly perfect, since the intermittent feeding would cause sideslips or skiddings and high tensile stresses on the web;

b. the intermittency will not allow to obtain high outputs owing to dwell and productive times; to this purpose, it should be noted that where dwell times, and accordingly sealing times, are reduced for output increase, there would be the serious risk of an increase in waste due to faulty sealing because of lack of time.

In another known type of machine the tube is continuously formed and the bags are obtained therefrom by cutting and sealing, provision being made for forwardly moving the tube on a horizontal platform, where tube lengths are cut. These lengths are individually gripped by electrically heated sealing pliers arranged on a drum or the like. The main disadvantage of this known ma chine resides in its complexity, particularly as to the control of temperature and supply for the rotatably driven pliers. A further disadvantage is that the horizontal movement of the tube would make it more difficult to cut the tube to lengths.

With respect to these two known types of machines, according to the invention, the tube continuously moves forward to the cutting station, the tube is cut into parts or lengths on a vertical path, so that the removal of the cut length is promoted by its own weight, the sealing is not allotted to rotating members, but is repeated several times on the same tube length.

There are also such machines as those referred to as form and fill" machines, not only providing for forming a bag from an intermittently advancing tube, as previously set forth, but also filling a bag with a metered amount of product, generally from an automatic weighing machine through the hollow mandrel. With respect to these prior art machines, a machine according to the invention provides perfectly squared up side bellows production with highly marked longitudinal pleats, stiffening the bag structure. Furthermore, the output is considerably higher because of separating the bag forming operation (which is at least partly continuous) from the filling and closing operation.

Other machines are known where a bag is formed by wrapping a length of material about a forming body. In these machines, bag forming depends on perfect planarity of the material length from which the bag is to be formed. Thus, for correctly operating with such a machine, it is required to accurately control all of those environment factors capable of affecting the material planarity, and to have an extra grade material. Conversely. in the machine and method according to the invention, the influence of external factors and material grade is substantially negligible.

It is the main object of the present invention to provide a machine and method for high rate bag production from a web of heat-scalable material.

It is another object of the present invention to provide a method and machine enabling a high rate in producing, filling and closing bags from a continuously moving web.

It is a further object of the present invention to provide an extremely compact bag producing, filling and closing machine.

A still further object of the present invention is to provide a machine in which, while with a high productivity, the feeding speeds of the bags from one processing station to another are relatively low, thus providing an extended life and greater reliability of the machine.

These and other objects, which will be more apparent from the following detailed description, are achieved by a method essentially characterized by consisting of:

a. folding the continuously advancing material so as to form a flattened tube, in the case provided with bellows, by overlapping the longitudinal edges of the material;

b. continuously sealing the tube at the overlapped edges;

c. cutting sections of a predetermined length from the continuously advancing tube;

d. intermittently forwardly moving said cut tube lengths, as aligned to one another, in a direction transversely of the tube feeding direction; and

e. during intermittent feeding dwells, transversely sealing said lengths at one end thereof, so as to close the same.

In order to carry out this method, a machine according to the invention is essentially characterized in that the continuously advancing material web is tubularly wrapped by edge overlapping on a fixed mandrel, preferably horizontal, and is then sealed at the overlapping zone by grazing along a heated bar, and then cut into lengths by a rotating knife, which lengths fall down on an intermittently operated conveyor carrying the same to a bottom sealing device operating during the conveyor dwells.

The invention will be more clearly understood from the following detailed description of a preferred em bodiment thereof, given by mere way of not limiting example and shown in the accompanying drawings, in which:

FIGS. 1A, 1B, and 1C show in a schematic side elevational view successive sections of the machine according to the invention, some parts thereof having been omitted, it being understood that the left end of FIG. 1B is a continuation of FIG. 1A and the right end of FIG. 1B is a continuation of FIG. 1C;

FIGS. 2A, 2B, and 2C show in a plan view the machine of FIGS. 1A 1C, still with some parts having been omitted, it being understood that the left end of FIG. 2B is a continuation of FIG. 2A and the right end of FIG. 2B is a continuation of FIG. 2C;

FIG. 3 is a schematic side elevational view of the device forming the tube from a heatsealable web;

FIG. 4 is a plan view of the device shown in FIG. 3, some parts thereof having been omitted;

FIG. 5 is a sectional view on a different scale, taken along the line V-V of HG. 4;

FIG. 6 is a fragmentary perspective view of a container or vessel for receiving a bag as formed, the container or vessel belonging to the first conveyor;

FIG. 7 is a schematic side elevational view of the device for sealing the bottom of the tubular lengths in the first conveyor;

FIG. 8 is a schematic side elevational view of the device for transferring the bags of the first conveyor to the intermittently rotating turret;

FIG. 9 is a schematic fragmentary vertical sectional view of the intermittently rotating turret and mechanisms for holding the bags and causing the opening of the mouth or inlet thereof;

FIG. 9A is a schematic plan view showing a portion of the mechanisms of FIG. 9;

FIG. 10 is a perspective view showing a detail of the second conveyor;

FIG. 11 is a schematic vertical sectional view of the passage location or station of the filled bags from the second conveyor to a transfer means and then to the means for carrying said bags to the mouth or inlet sealing station and to the outlet;

FIG. 12 is a schematic plan view of the transfer means;

FIG. 13 is a plan view of the cross member carrying the means for conveying the bags to the mouth or inlet sealing station; and

FIG. 14 is a vertical sectional view of a different conveying means.

The heat-scalable material S, such as a laminate, the inner layer of which is a heat-sealable material, for example polyethylene, is drawn from a reel 1 and follows the path shown by the arrows, this path extending on the idle rollers IA, IB and 1C, carried by the machine frame 200, comprising two sides 201, between which the lower path of the web 8 extends. After the last deflection by the roller 1C, the web is continuously tubularly wrapped about a per se known mandrel 2, carried by the machine frame through an arm 2A mounted between a pair of shoulders 28 of said frame.

The mandrel 2 (FIGS. 3 comprises a metal plate 3A which at its rear end is curved and connected through a core 38 to a second plate 3C, substantially parallel with the first plate 3A, but approaching closer thereto to the outlet end.

Sidewise of the mandrel, two sets of thinned edge idle rollers 3 are provided and carried on spindles 3D attached to the machine frame. These rollers 3 enter the gap between said two plates 3A and 3C and provide for forming bellows or pleats in the tube sides (FIG. 5).

In order to obtain the double folding of one of the tube edges, offset or cantilevered plates 700 secured to the machine are conventionally used.

Two square elements 300 cooperate with the mandrel 2 by acting on the material S, the bent ends of these square elements causing the rims of the material S to overlap one another, so as to make the tube. Said square elements 300 are attached to the machine frame. Square elements 301 are attached to said frame and on the bent sides thereof carry idle rollers 302, the rotational plane of which is skew relative to a vertical plane through the mandrel axis.

Above the mandrel 2, and more particularly above the overlapping zone for the rims of material S (FIG. 5), a bell-crank lever 5A is pivoted at 5 to the frame, at the lower end this level having a heated blade or bar 4, thermostatically adjusted as to its temperature, this blade or bar extending parallel with the overlapping zone of the edges of material S. For example, the hot blade is heated by an incorporated resistance 4A.

Under the action of a jack 6, which is pivoted between said lever 5A and the machine structure, the bar 4 is kept contacting the overlapping zone of the edges of material S to provide for heat-sealing. When required, the double acting type of pneumatic jack 6 is effective to separate the bar 4 from the material.

At the left-hand side of FIG. 3, a lever 7A is pivoted to said blade 4, at the end this lever 7A carrying an idle roller 7 adhering to the sealed zone by means of a compression spring 7B. The material S, due to the feeding traction exerted thereon by a driven drum 8 cooperating with a pressure roller 9, slides along the lower surface of heated bar 4 and on the mandrel 2, with sealing takes place at the overlapped edges, thus providing a tube. The drum 8 is driven by a gear train 8A driven by a drive unit 8B within the machine frame.

The tube (still designated at S) passes from the hori' zontal position, where the mandrel 2 is located, to an inclined position and passes on an idle cylinder 10 op erated through a chain and sprocket drive 10A by said drum 8.

A pressure cylinder 10B coacts with said drum 10, by resiliently pressing against the tube. In its vertical movement the tube S reaches between two knives 11, 11A, accomplishing the function of cutting tube sections of a predetermined length, thus producing successive flattened tubular sections or lengths provided with side pleats. The knife 11A is stationary and attached to the machine frame, while the other knife II is carried on a cylinder 11B which continuously rotates and is driven by a geared motor, not shown, through a conventional mechanical gear connection, also not shown.

The cut tube lengths, generally designated at 12, fall down on a first conveyor, designated as a whole at 13, which is intermittently forwardly driven.

This conveyor 13 comprises a set of containers I4 (FIG. 6) that are closed on three sides only.

In order to prevent said lengths 12 from falling down from the respective container 14 both under the cutter and for some distance of the conveyor to the next transferring station, two parallel bars 16 are provided as fixedly carried by the machine frame and slightly pressing the length 12 against the wall 14A of the container 14, taking advantage of the yielding capability of the chains 143, to which the containers are attached.

In FIG. 6, it will be seen that one of said bars 16 is located at the low portion of the container, while the other bar is effective against the high portion thereof. These bars pass through two slits provided on the opposite parallel side walls of the container 14.

At some mutual distance from one another, the several containers 14 of the first conveyor 13 are attached on a pair of parallel chains 14A, which are driven on several pairs of sprockets 27, 27A and 27B so arranged that the conveyor, when seen in a plan view (FIGS. 2A and 28), will substantially form a pentagon having unequal sides, one vertex of which is below the cutter 1 1, 11A and one side of which, opposite to said vertex, is at a transferring device, discussed below. This last mentioned side, between the pairs of idle sprockets 27A (FIG. 2B), has such an extension during the dwells as to enclose two containers 14 arranged in the same vertical plane. The intermittent movement is provided by the pair of sprockets 278, while the other pairs are idle. The pair of sprockets 27B are also driven by the drive unit 8B through one of the kinematic means controlling the motion of said web S and a chain drive 400, the latter driving a programming screw mechanism impressing the required intermittency to the pair of sprockets 27B.

During the dwell times, at a certain position for one side of the polygon formed by the first conveyor 13, the tube lengths are sealed at the bottom, that is at the zone shown by dashed lines at 12A in H6. 6. Sealing operation is accomplished by the device schematically shown in FIG. 7, which device is located at the position G shown in FIGS. 2A and 2B.

The transverse sealing 12A for the bag bottom occurs when the lower end of the length 12, extending below the container 14, interposes between a heated bar 17 attached to the machine frame and a movable bar 18 which reciprocates in time with the motion of the conveyor 13 through the primary shaft 402 of the programming screw driving the conveyor 13.

This primary shaft carries a crank 19 controlling through the connecting rod 20 a rocking lever 21 pivoted at 22 to link rods 23 transmitting the thrust via the pivot pin 24 to a lever 25 rotatable about a fixed pivot 25A, ajaw 18A carrying said movable bar 18 and also rotating thereabout. Through a compression spring 26 the thrust is transmitted from the lever 25 to the jaw 18.

Conveniently, said two bars 17 and 18 have a length sufficient to engage more than two bags at a time, with the result that the bottom of each bag is subjected repeatedly to the sealing action of the bars 17 and 18. The two bars have a further separate section 17B and 18B, respectively, which is cooled by water circulation.

When the bottom sealed bags are at the position between the pairs of idle sprockets 27A, the bags are gripped on the bottom projecting below the relative containers 14 to be transferred against the face of a polygonal turret 28 (FIG. 2B).

The mechanism gripping two bags at a time and transferring the gripped bags to the turret consists of two pairs of pliers 29, each pair being assigned for transferring one bag. The pliers comprise two jaws 29A and 29B. The jaws 29B are secured on a shaft 29C (FIG. 8), and the jaws 29A are secured on a shaft 29D. The two shafts are connected by a pair ofintermeshing pinions 30, one pinion for each of the shafts. A rack 31 engages one of said pinions and is operated by a pneumatic piston 32, which along with the pliers 29 is carried by a bracket 33 reciprocating between the first conveyor 13 and the turret 28. This bracket 33 is pivoted to the ends of two levers 34 comprising two sides of an articulated parallelogram, of which the fourth fixed side is the line joining the pivoting points 34A to a bearing 34B carried by the machine frame. One of said levers extends beyond the pivoting point 34A and is articulated to a linkage 35 including a lever 35B pivoted to the machine frame and having an end roller 35C entering the groove of a cam 36 driven by the drive unit 8B.

On the rear, said bracket has a driving tooth 37 engaging the pawl of a ratchet 38 connected with a linkage 39.

Said linkage 39 comprises inter alia a lever 39A pivoted to the machine frame and having at its free end a pair of fingers 398 which. as shown in FIG. 8, hold the top ends of the two bags 12 to be transferred in contact with the wall 14A of the container 14 until the bag transferring operation starts.

The transfer operation is as follows.

After two bags have reached the transfer station, wherein the pliers are open, the pliers 29 close on the bottom of the two bags by means of the pneumatic jack 32 driven by a pneumatic slide valve (not shown) which is controlled by a cam secured to the shaft of cam 36 rotating through one revolution for every two bags.

Thereafter, the cam 36 moves the bracket 33 towards the turret and through the tooth 37 raises the lever 39A, so that the teeth 39B thereof do not interpose in the bag path.

During the transfer step, the bag mouth or inlet spreads or opens, owing to the intrinsic resiliency of the material comprising the bag. This is taken advantage of for allowing the two transferred bags to be suitably re tained against one of the faces of said turret 28. When, as it will be more fully understood in the following, the two transferred bags are pressed to the wall of turret 28, the pliers 29 open due to operation of the pneumatic jack 32, releasing the lower end of the bags. Then, the bracket 33 moves with the pliers 29 open back to the position shown in FIG. 8 to start a new operating cycle.

The turret 28, as shown in the drawings, is of hexagonal prismatic shape and intermittently operated by said drive unit 8B through a programming screw (not shown). In order to retain the bags at the turret, each face of the latter (FIGS. 9 and 9A) is provided with a bag retaining and bag mouth or inlet spreading unit 40. This unit 40 comprises holder 41, the end of which is configurated as a fork, so that a bag is retained by each leg of the fork. The unit also comprises a double-fork spreader member 42 (FIG. 9A), so that each pair of legs thereof provides for enlarging (spreading) the mouth or inlet for one of the two bags retained on the involved face. The mouth or inlet spreading of the bags retained by the holder 41 is accomplished as the turret rotates in order that the entire dwell time is available for filling up the bags with the desired product at the filling station.

When the pliers 29 have moved the pair of bags 12 near the face of said turret 28, the unit 40 is at the position 40A, shown by broken lines, that is raised from the face. When the bags are close to the turret face and before being released from the pliers 29, the unit 40 rotates about the shaft 43, clamping the pair of bags, as shown by full lines in FIG. 9.

The following mechanism is provided for the rotational movements about the shaft 43. One arm of the holder 41 is connected through a link rod 45 to a rod 46, at the bottom terminating with a finger 47. This finger is intended to be engaged by a head 48, vertically movable along the bearing 48A and carried at the upper end of a rod 48B, the latter being connected by a link rod 48C to a rocking lever 48D, a grooved cam 49 acting thereon through a linkage 49A. This rocking lever serves also the purpose of controlling a second head 485 which is at an opposite position and serves for unloading the filled bags from the turret 28. The assembly comprising the heads 48 and 48S and the associated operating members do not partake of the turret rotation.

The rod 46 forms a side of an articulated parallelogram of link rods 51 pivoted on the inner side of the face of said turret 28.

A traction spring 44 tends to upward return the rod 46. When the head 48 is at the uppermost raised position, as shown by full lines in FIG. 9, the unit 40 is at the position shown by full lines in the figure. Conversely, when the head 48 is at lowered position, due to its engagement with the finger 47, the unit 40 is at the position 40A shown by broken lines. This is the position taken by the unit 40 when the pliers 29 have ap plied the bag to the face of the drum or turret 28.

Before the jaws or pliers open and move away from the turret 28, the head 48 raises and the unit 40 enters the mouth or inlet of the bags 12, thus clamping one side of the bag against the turret face.

The turret 28 is then stepped towards a station K. This stepwise movement is controlled by the drive unit 88 operating upon the hollow shaft 28A through the cross member 28B carrying the turret 28. During this movement, the spreading member 42 moves to the position shown by broken lines, further spreading apart the mouth or inlet of the bag 12. This relative movement of the spreading member 42 and holder 41, the latter remaining at the clamping and holding position of the bag 12, results because of the spreading member 42 forms the side of a further articulated parallelogram of link rods 52, the fourth side of which is formed by the extension of the holder 41, and the provision at the end of said member 42 for a roller 54 driven by a grooved cam 55, the latter being attached to a stationary shaft 56, extending along the hollow drive shaft 28A and supporting the latter by means of bearings 57. A traction spring 53 is disposed between the member 42 and holder 41. The cam 55 is shaped so as to produce this relative movement of said member 42 and pliers 41.

Thus, the first parallelogram (46, 51) allows a concurrent movement of the member 42 and holder 41, while the second parallelogram provides for the relative movement of said member 42 and pliers 41.

At the station K, there is located a per se known device (described in the Italian Pat. No. 863,660), comprising two pairs of movable blades, each of which penetrates into the bag causing the squaring of the bottom thereof. Upon squaring completion, the turret 28 is forward stepped or indexed and carries to the station Z the two bags previously squared at the station K. At this station, the mouth or inlet is maintained still open by the spreading member 42. It should be noted that said spreading member is of a much reduced width, thus involving a negligible portion of the surface of the bag mouth or inlet. At this station Z, there is provided a device comprising a set of four numbers of automatic weighing machines 500, two by two supplying the metered material from a hopper 502 to outlet conduits 501. This device Z is carried by a column 503 (FIG. 18) forming part of the machine frame and is located so that each of the two outlet conduits 501 have the opening thereof below the open mouth or inlet of a bag. High speed automatic weighing machines of any known type may be used, but those preferably used are de scribed in the Italian Pat. No. 898,501 and in the issued German Pat. application No. 2,112,214 corresponding to the Italian patent and to which reference can be made for further details. The operation of the automatic weighing machines occurs, for example, just as the turret stops through the operation of an electrical contact, not shown.

Upon bag loading completion, the turret is indexed and carries the bags to the station X, where the bags are unloaded on a second conveyor 59, to be described in the following.

On the passage from the station Z to the unloading station X, the spreading member approaches the holder 41 as a result of the configuration of said cam 55. Upon reaching the station X, the finger 47 will be below the head 488. The latter is lowered under the action of cam 49, drawing the rod 51 therewith and causing the unit 40 to raise concurrently about the pivot 43, which unit moves to a position similar to the position 40A shown by broken lines in FIG. 9. Upon this rotation of said unit 40, the bags are released. Then, the unit 40 will move back to the original position as the head 48S raises.

The two released bags (FIG. 10) fall down into coupled containers attached to pairs of chains 59A. This falling causes the compaction of the product without any need of vibrators. The chains 59A and the set of coupled containers 58 form the second conveyor 59 following a horizontal polygonal path.

The containers 58 are closed on all of the sides thereof, except for the top and bottom sides. During the movement thereof in the coupled containers 58, the bags run on a bearing surface 60 secured to the machine in any known manner.

This surface starts shortly before the station X and extends through a short length of the path of said second conveyor 59. The chains 59A are driven by pairs of sprockets 61, 61A, 61B so arranged as to impart the polygonal configuration to the conveyor, and more particularly, such that a vertex is formed by a coupled container 58 at the position where the filled bags fall down from the turret 28, whereas another side, opposite to the processing vertex and between the pairs of sprockets 61A, is of such extension to contain in dwell times two coupled containers 58, that is four bags. The pairs of sprockets 61, 61A and idly carried by vertical shafts secured to the machine frame, and the pair of sprockets 61B is intermittently operated from unit 88 through the same programming screw driving the turret 28.

It should be noted that the second conveyor 59 is indexed by a step substantially equal to a coupled container 58 for every two steps of the first conveyor 13, and that within the conveyor length between the pairs of sprockets 61A, the bag unloading on underlying transfer means, to be discussed in the following, occurs every two dwells of the second conveyor 59, that is to say every four dwells of the first conveyor 13.

Every two dwells of the second conveyor 59, four bags are unloaded at the station W corresponding to the length between the two pairs of sprockets 61A.

Unloading is accomplished as follows.

At the station W (FIG. 11 the surface 60 on which the bags 12 bear continues with a length 60A that can be displaced in the direction shown by arrows F by operation of a double-acting pneumatic jack 63. When the length 60A is leftward displaced, as viewed in FIG. 11, which occurs every two dwells of the second conveyor 59, the four no longer supported bags 12 fall down from the two coupled containers 58 on underlying transfer means 62. These transfer means 62 have two chambers 62A and 628, each of which capable of accommodating a row of four bags. The two chambers 62A and 62B are bottom-open and the bottom openings can be closed or opened by a wall 67 controlled by a doublcacting pneumatic jack 68. The width L of the movable bottom 67 is about 1.5 times the width of said transfer means 62.

The transfer means 62 are carried by parallel side guides 62C and can be moved in the direction shown by arrows F by a doubleacting pneumatic jack 63Z. Within each of the chambers 62A and 62B longitudinal walls 64 are provided and operated by double-acting pneumatic jacks 66 (FIG. 12).

Each of said chambers also have a pair of transverse walls 65, each of which are operated by said doubleacting pneumatic jacks 66. These jacks 66 are carried by said transfer means 62.

When the transfer means 62 are completely empty, the chamber 628 is below the containers 58 at the unloading station. The bottom 60A is moved, whereby the four bags fall down into the chamber 62B. Thereafter, the jack 63Z moves the transfer means 62 to the right, that is to the position shown in FIG. I]. It should be noted that immediately after the bags on the second conveyor 59 are unloaded and before said conveyor starts to move forward, the bottom 60A returns to closed position. After two forward steps of the second conveyor 59, further four bags will reach the station W. Then, as above described, these further four bags are unloaded, but into the underlying chamber 62A of said transfer means 62.

Thus, the transfer means 62 are successively loaded, so that first the transverse walls 65 and then the longitudinal walls 64 are forced against the bags by the jacks 66. The bag contents are thus compacted along the four faces of the bags, with the result that the vertical sides of each bag assume a substantially planar shape and are substantially at right angles to one another. This significantly simplifies the bag boxing operations.

Following compaction, the walls 64 and 65 are removed from the bags, and then the bottom 67 is opened. The bags fall down into an underlying vessel 69 which along with three other identical vessels is supported at the forked end of the arms of a cross member 70. Laterally of the vessels 69, two guide eyelets 69A are provided and threaded on columns 69B attached to the cross member arms. The vessels 69 can be moved along the columns 698 and normally bear on the arm forks.

More particularly, the cross member has four arms and thus are the vessels 69 angularly spaced apart from one another through 90. The cross member is oper ated by a drive unit 600 through a programming screw 601, so as to be forward moved or indexed by one step every four steps of the second conveyor 59, and hence every eight steps of the first conveyor 13. The vessels 69 are identical to one another and can be made as shown at the bottom of FIGv 11 when a compaction of the contents is not required also in the vertical direction of the bag, or as shown in FIGS. 13 and 14, when such a compaction is instead required. The vessel 69 of FIG. 11 substantially corresponds to the transfer means 62, with only the differences of having a closed bottom and the omission of the transverse compacting walls 65. Thus, the vessels 69 are provided only with the longitudinal movable walls 71 operated by jacks 72.

When the vessel 69 is loaded, the cross member moves through 90 to a first position P, and then to a second position, where a per se known bell head 88 is provided exactly above a vessel 69 at each of the cross member dwells. At the beginning of each of the dwells, the vessel under the bell is raised by a lower fixed jack 301 and sealingly applied against the head opening. By a conduit 304 connected to a vacuum source, the air within the head is evacuated. The heat sealing of the bag mouth or inlet is assigned to thermostatically heated bars comprising a fixed central bar305 and two parallel movable bars 306 applying against the bag rows by operation of jacks 307.

Upon completion of the bag mouth or inlet Sealing, the vessel is lowered and then the cross member is indexed by one step and carries a vessel to the unloading station H, where either manually or by any known means the eight bags are removed from the vessel.

When desiring a vertical compaction of the bags, the vessel 69A of FIGS. 13 and 14 can be used instead of the vessel 69. In addition to having longitudinal walls 71A, along with the associated operating jacks 72A, corresponding to the former vessel 69, this vessel 69A has shafts 73 at two opposing sides on the top thereof carried on bearings. not shown.

At one end (see plan view of FIG. 13), each of the shafts 73 has a pinion 75 meshing with a rack 76 operated by a double-acting pneumatic jack 77.

Each of the shafts 73 carry a compacting blade 74 which, as said shafts rotate. acts upon a portion of the upper face of the bag 12. Two concentric shafts 78 and 79 are rotatably carried above the intermediate wall of the vessel 69A, each of said shafts having blades 80 and 81, respectively, attached thereto.

As apparent, the external shaft 79 will have peripheral slits for the passage of corresponding extensions, by which the blade 80 is connected to the internal shaft 78. Through a pinion 82 and rack 83 said internal shaft 78 is operated by a jack 84 attached to the vessel. The shaft 79 is operated through a rack 86 and pinion 87 by a double-acting pneumatic jack which, as the other jacks, is carried on the vessel. By causing the operation of the several jacks, for example when the vessel 69A arrives at the position or station P, the blades will rotate and press against the upper face of the bags.

As shown in FIG. 14, a clearance or gap is left between the two blades acting upon the same row of bags, through which clearance or gap the unfilled upper end of the bag can freely exit. The operation of the several jacks is controlled by slide valves, the latter being acted upon by cams operated by the drive unit 600.

Although only one embodiment of the invention has been described, those skilled in the art can now readily devise many changes and modifications which, however, are all to be intended as within the scope of the invention.

What I claim is:

1. In a method for making and filling bags, the steps of manufacturing a series of bags from a strip of sheet material while conveying the thus-manufactured bags with a first conveyer during a first conveying operation at least during the last stage of manufacture of the bags in a stepwise manner according to which predetermined advance and dwell intervals alternate with each other, conveying the thus-manufactured bags with a second conveyer during a second conveying operation to a filling station, with the conveying of the bags to the filling station also being carried out in a stepwise manner according to which predetermined advance and dwell intervals alternate with each other, delivering a plurality of the manufactured bags to said second conveyer at each dwell interval of said second conveying operation while providing for a dwell and advance interval during said second conveying operation a total time which is a multiple of the total time provided for a dwell and advance interval during said first conveying operation, and simultaneously filling each plurality of bags delivered to said second conveyer during a dwell interval of said second conveying operation, so that each bag may be filled during an interval substantially longer than the dwell interval of the first conveying operation to gain additional filling time without retarding the rate of manufacture of the bags.

2. in a method as recited in claim 1 and including the steps of conveying the filled bags with a third conveyer during a third conveying operation to a bag-closing station with said third conveying operation also having predetermined advance and dwell intervals which alternate with each other, delivering to the third conveyer during each dwell interval of said third conveying operation a number of filled bags which is a multiple of the plurality of manufactured bags delivered to the second conveyer at each dwell interval of the second conveying operation, and simultaneously closing at the bagclosing station said number of filled bags which is a multiple of said plurality of manufactured bags, so that the rate of operation of the third conveyer may be reduced as compared to the rate of operation of the second conveyer.

3. In a method as recited in claim 1 and wherein said last stage of manufacture of the bags includes the step of conveying the latter in said stepwise manner with the bags all having free ends projecting beyond the first conveyer, and said last stage of manufacture including the step of simultaneously sealing said free ends of a plurality of the bags which extend along a given row during each dwell interval of said first conveying operation with each bag requiring a time equal to a number of said dwell and advance intervals of said first conveying operation to move beyond a sealing structure which seals said free ends of said bags in said row, whereby each bag is subjected at said free end thereof to a plurality of sealing operations during said first conveying operation.

4. In a method as recited in claim 1 and wherein the strip of sheet material is first formed into a fiat tube, and including the step of directing said flat tube downwardly toward said first conveyer while cutting across the flat tube which extends downwardly to form individual lengths therefrom, and freeing the cut lengths to fall by gravity to said first conveyer while the cut lengths remain in the vertical attitude which the flat tube has just prior to cutting thereof into said lengths.

5. In a method as recited in claim 4 and including the step of supporting the filled bags on a slide surface along which the bags are advanced while being delivered to the third conveyer, with the bags being delivered to a location situated over said third conveyer, and removing a part of the slide surface from beneath the bags when they arrive at a location over the third conveyer so that the bags fall by gravity to the third conveyer to compact material in the bags while they fall to the third conveyer.

6. In an apparatus for manufacturing and filling bags, manufacturing means for manufacturing a plurality of bags from a strip of sheet material, said manufacturing means including a first conveyer means for conveying the bags at least during the last stage of the manufacture thereof in a stepwise manner having predetermined dwell and advance intervals, filling means for filling a plurality of the thus-manufactured bags simultaneously while said plurality of bags remain stationary, second conveyer means for conveying the manufactured bags to said filling means in groups each of which is made up of said plurality of bags which are simultaneously filled by said filling means, with said second conveyer means having predetermined dwell and advance intervals according to which successive groups of bags are filled during each dwell interval of said second conveyer means, and delivering means for delivering a plurality of manufactured bags equal to the number of bags filled by said filling means at each dwell interval of said second conveyer means to said second conveyer means from said first conveyer means during each dwell interval of said second conveyer means while said first conveyer means carries out a number of dwell and advance cycles equal to the plurality of bags filled simultaneously by said filling means, whereby relatively long dwell intervals for filling the bags are gained without reducing the rate of manufacture of the bags.

7. The combination of claim 6 including a bagclosing means for simultaneously closing a number of filled bags which is a multiple of the plurality of bags forming each group simultaneously filled by said filling means, third conveyer means for conveying the filled bags to said bag-closing means in a stepwise manner having predetermined dwell and advance intervals, and transfer means cooperating with said second and third conveyer means for transferring said number of filled bags from said second to said third conveyer means during each dwell interval of the latter, whereby the dwell intervals of said third conveyer means are longer than the dwell intervals of said second conveyer means so that the speed of operation of said third conveyer means is less than the speed of operation of said second conveyer means.

8. The combination of claim 6 and wherein said first conveyer means conveys the bags in said stepwise manner during said last stage of manufacture thereof in a manner according to which said first conveyer means holds the bags while leaving free end portions thereof exposed beyond said first conveyer means with said free ends arranged in a row, and sealing means situated in the path of movement of said row of free ends for simultaneously sealing the latter while said first conveyer means conveys each bag through a number of dwell and advance cycles before each bag moves beyond said sealing means so that each bag is sealed at its free end by a number of sealing operations provided by said sealing means.

9. The combination of claim 6 and wherein said bag manufacturing means first provides a fiat elongated tube of sheet material from the strip of sheet material and delivers the flat tube of sheet material to a location from which the flat tube of sheet material hangs down toward a receiving portion of said first conveying means, said manufacturing means including a cutting means for cutting across the hanging portion of the tube of sheet material to provide therefrom predetermined lengths which successively fall to said receiving portion of said first conveyer means.

10. The combination of claim 6 and wherein said second conveyer means has the construction of a rotary turret of polygonal configuration having a number of substantially straight sides at each of which said delivering means delivers said group of bags from said first to said Second conveyer means, and opening means carried by said turret at each of said sides thereof for opening the plurality of bags at each side of said turret at a top part of said bag before the plurality of bags reach said filling means. I

11. The combination of claim and wherein said bag-opening means includes a parallelogram linkage having a holding means for holding one wall of the bag against a side of the turret and a movable bag-opening element for displacing an opposite wall of each bag away from said one wall thereof, and cam means coopcrating with said parallelogram linkage for operating the latter to open the bags while they are held against the turret by the holding means.

12. The combination of claim 7 and wherein said transfer means includes a wall engaging the bottom ends of the filled bags and along which the filled bags slide while they are transferred by said transfer means from said second to said third conveyer means, said wall being situated over a receiving portion of said third conveyer means and having over said receiving portion of said third conveyer means a removable portion of said wall, and removing means operatively connected to said removable portion of said wall for displacing said removable portion from beneath bags over said receiving portion of said third conveyer means so that the bags then fall to said third conveyer means to have material in the bags compacted while the bags are received by said third conveyer means. 

1. In a method for making and filling bags, the steps of manufacturing a series of bags from a strip of sheet material while conveying the thus-manufactured bags with a first conveyer during a first conveying operation at least during the last stage of manufacture of the bags in a stepwise manner according to which predetermined advance and dwell intervals alternate with each other, conveying the thus-manufactured bags with a second conveyer during a second conveying operation to a filling station, with the conveying of the bags to the filling station also being carried out in a stepwise manner according to which predetermined advance and dwell intervals alternate with each other, delivering a plurality of the manufactured bags to said second conveyer at each dwell interval of said second conveying operation while providing for a dwell and advance interval during said second conveying operation a total time which is a multiple of the total time provided for a dwell and advance interval during said first conveying operation, and simultaneously filling each plurality of bags delivered to said second conveyer during a dwell interval of said second conveying operation, so that each bag may be filled during an interval substantially longer than the dwell interval of the first conveying operation to gain additional filling time without retarding the rate of manufacture of the bags.
 2. In a method as recited in claim 1 and including the steps of conveying the filled bags with a third conveyer during a third conveying operation to a bag-closing station with said third conveying operation also having predetermined advance and dwell intervals which alternate with each other, delivering to the third conveyer during each dwell interval of said third conveying operation a number of filled bags which is a multiple of the plurality of manufactured bags delivered to the second conveyer at each dwell interval of the second conveying operation, and simultaneously closing at the bag-closing station said number of filled bags which is a multiple of said plurality of manufactured bags, so that the rate of operation of the third conveyer may be reduced as compared to the rate of operation of the second conveyer.
 3. In a method as recited in claim 1 and wherein said last stage of manufacture of the bags includes the step of conveying the latter in said stepwise manner with the bags all having free ends projecting beyond the first conveyer, and said last stage of manufacture including the step of simultaneously sealing said free ends of a plurality of the bags which extend along a given row during each dwell interval of said first conveying operation with each bag requiring a time equal to a number of said dwell and advance intervals of said first conveying operation to move beyond a sealing structure which seals said free ends of said bags in said row, whereby each bag is subjected at said free end thereof to a plurality of sealing operations during said first conveying operation.
 4. In a method as recited in claim 1 and wherein the strip of sheet material is first formed into a flat tube, and including the step of directing said flat tube downwardly toward said first conveyer while cutting across the flat tube which extends downwardly to form individual lengths therefrom, and freeing the cut lengths to fall by gravity to said first conveyer while the cut lengths remain in the vertical attitude which the flat tube has just prior to cutting thereof into said lengths.
 5. In a method as recited in claim 4 and including the step of supporting the filled bags on a slide surface along which the bags are advanced while being delivered to the third conveyer, with the bags being delivered to a location situated over said third conveyer, and removing a part of the slide surface from beneath the bags when they arrive at a location over the third conveyer so that the bags fall by gravity to the third conveyer to compact material in the bags while they fall to the third conveyer.
 6. In an apparatus for manufacturing and filling bags, manufacturing means for manufacturing a plurality of bags from a strip of sheet material, said manufacturing means including a first conveyer means for conveying the bags at least during the last stage of the manufacture thereof in a stepwise manner having predetermined dwell and advance intervals, filling means for filling a plurality of the thus-manufactured bags simultaneously while said plurality of bags remain stationary, second conveyer means for conveying the manufactured bags to said filling means in groups each of which is made up of said plurality of bags which are simultaneously filled by said filling means, with said second conveyer means having predetermined dwell and advance intervals according to which successive groups of bags are filled during each dwell interval of said second conveyer means, and delivering means for delivering a plurality of manufactured bags equal to the number of bags filled by said filling means at each dwell interval of said second conveyer means to said second conveyer means from said first conveyer means during each dwell interval of said second conveyer means while said first conveyer means carries out a number of dwell and advance cycles equal to the plurality of bags filled simultaneously by said filling means, whereby relatively long dwell intervals for filling the bags are gained without reducing the rate of manufacture of the bags.
 7. The combination of claim 6 including a bag-closing means for simultaneously closing a number of filled bags which is a multiple of the plurality of bags forming each group sImultaneously filled by said filling means, third conveyer means for conveying the filled bags to said bag-closing means in a stepwise manner having predetermined dwell and advance intervals, and transfer means cooperating with said second and third conveyer means for transferring said number of filled bags from said second to said third conveyer means during each dwell interval of the latter, whereby the dwell intervals of said third conveyer means are longer than the dwell intervals of said second conveyer means so that the speed of operation of said third conveyer means is less than the speed of operation of said second conveyer means.
 8. The combination of claim 6 and wherein said first conveyer means conveys the bags in said stepwise manner during said last stage of manufacture thereof in a manner according to which said first conveyer means holds the bags while leaving free end portions thereof exposed beyond said first conveyer means with said free ends arranged in a row, and sealing means situated in the path of movement of said row of free ends for simultaneously sealing the latter while said first conveyer means conveys each bag through a number of dwell and advance cycles before each bag moves beyond said sealing means so that each bag is sealed at its free end by a number of sealing operations provided by said sealing means.
 9. The combination of claim 6 and wherein said bag manufacturing means first provides a flat elongated tube of sheet material from the strip of sheet material and delivers the flat tube of sheet material to a location from which the flat tube of sheet material hangs down toward a receiving portion of said first conveying means, said manufacturing means including a cutting means for cutting across the hanging portion of the tube of sheet material to provide therefrom predetermined lengths which successively fall to said receiving portion of said first conveyer means.
 10. The combination of claim 6 and wherein said second conveyer means has the construction of a rotary turret of polygonal configuration having a number of substantially straight sides at each of which said delivering means delivers said group of bags from said first to said second conveyer means, and opening means carried by said turret at each of said sides thereof for opening the plurality of bags at each side of said turret at a top part of said bag before the plurality of bags reach said filling means.
 11. The combination of claim 10 and wherein said bag-opening means includes a parallelogram linkage having a holding means for holding one wall of the bag against a side of the turret and a movable bag-opening element for displacing an opposite wall of each bag away from said one wall thereof, and cam means cooperating with said parallelogram linkage for operating the latter to open the bags while they are held against the turret by the holding means.
 12. The combination of claim 7 and wherein said transfer means includes a wall engaging the bottom ends of the filled bags and along which the filled bags slide while they are transferred by said transfer means from said second to said third conveyer means, said wall being situated over a receiving portion of said third conveyer means and having over said receiving portion of said third conveyer means a removable portion of said wall, and removing means operatively connected to said removable portion of said wall for displacing said removable portion from beneath bags over said receiving portion of said third conveyer means so that the bags then fall to said third conveyer means to have material in the bags compacted while the bags are received by said third conveyer means. 